How does a corvette heater control valve work?
Of course, if you’ve been underneath your dash doing work…there are four different actuators that deliver vacuum to the plenum doors that permits hot and cold air to flow from anyone of those dozen grilles. Your 81 is similar to my 78 and I’m assuming its an air car. If you have questions…feel free to ask.
Where is the hot water heater valve located?
It is located on the passenger side near the back of the engine in one of the heater lines. You should be able to move valve with your hand. Once engine is up to temperature, feel both sides of heater hose before and after valve. it should be hot on both sides if water is flowing. If not move valve and see if it gets hot on both sides.
Where is the heater valve on a Ford Explorer?
AS you know…Most Ford explores have a vacuum operated valve in the heater line to the heater. It is located on the passenger side near the back of the engine in one of the heater lines. You should be able to move valve with your hand.
Why does a control valve not move in the closed direction?
Due to static friction (again), the valve will not immediately respond by moving in the closed direction. Instead, it will hold still until enough pressure has been released to diminish actuator force to the point where there is enough unbalanced spring force to overcome static friction in the downward direction.
What can cause a heater control valve to fail?
A heater control valve can fail in several ways. Since a vacuum operated valve defaults to the fully open heat-on position when vacuum isn’t applied, a loss of vacuum is the first thing to suspect in a “heat always on” condition. The loss of vacuum can be caused by a break in a vacuum line or a faulty vacuum switch.
What causes a vacuum to go out on a heater?
Since a vacuum operated valve defaults to the fully open heat-on position when vacuum isn’t applied, a loss of vacuum is the first thing to suspect in a “heat always on” condition. The loss of vacuum can be caused by a break in a vacuum line or a faulty vacuum switch. To repair a faulty switch, you sometimes have to replace the heater control.
How to check the temperature of a heater control valve?
Then check the temperature of the hose on the inlet and outlet sides of the heater control valve. The inlet and outlet hoses should be the same temperature. If the inlet side is warmer than the outlet side, the valve isn’t opening or opening fully. Remove the vacuum line from the vacuum motor and check for engine vacuum.
What to do if your heater control valve breaks?
On a cable operated system, the cable can break or detach from the control levers, leaving the valve in the fully open position. Adjust the heat to the full on position with the engine at operating temperature. Then check the temperature of the hose on the inlet and outlet sides of the heater control valve.